log message in exception level when path encoding errors happen.

Original code is kind of except-pass. This will ignore the error
occurs in process of encoding path. And if such error happened
without any information in logs, developer have to debug in a
long distance from error stack. That's wasting time, so there
should be a logging message here.

Fixes: bug #1123048
Change-Id: I7941b524e936241fb8d62fad5ad90de3daffe5e7
Merge "log message in exception level when path encoding errors happen."